Azo-dyestuffs



United States Patent AZO-DYESTUFFS Christian Zickendraht, Binningen, andArthur Buehler, Rlreinfelden, Switzerland, assignors to Ciba Limited,Basel, Switzerland, a Swiss firm No Drawing. Application May 3, 1954,Serial No. 427,361

Claims priority, application Switzerland May 5, 1953 11 Claims. (Cl.260-147) R1 represents a benzene radical bound to the azo-linkage inortho-position relatively to the hydroxyl group, R2 represents ahydrogen atom, or an alkyl or benzene radical, and R3 represents an arylradical, and

in which at least one of the aromatic radicals in the dyestufi moleculecontains a substituent not imparting solubility in water, with an agentyielding cobalt or chromium under conditions such that a metalliferousazo dyestufli is obtained which contains less than one atom of cobalt orchromium in complex union per molecule of monoazodyestufi.

The monoazo-dyestufis of the above general formula (1) serving asstarting materials in the present process can be obtained by coupling an.ortho-hydroxy-diazo compound of the benzene series which is free fromsulfonic acid and carboxylic acid groups with a 3-aryl-5- pyrazolone,and so selecting the starting materials that the resultingmonoazo-dyestufi contains, in addition to'a -SO2NH2 group, at least onearomatically bound substituent not imparting solubility in water,advantageously a nitro, alkoxy or alkyl group or a halogen atom.

As ortho-hydroxy-diazo-compounds of the benzene series there come intoconsideration for the preparation of the dyestuffs serving as startingmaterials in the present process, on the one hand, compounds which arefree from sulfonic acid amide groups, such as the diazo compounds of4-ch1oro-, 4- or-5-nitro-, 4:6-dichloro-2-aminol-hydroxybenzene or4-nitro-6-chloro-2-amino-l-hydroxybenzene, which are to be coupled with3-ary1-5-pyrazolones, containing a SOzNH2 group, such as- 1:3-diphenyl-S-pyrazolone-2'-, 3- or 4'- sulfonic acid amide..Advantageously, there are used ortho-hydroxy-diazocompounds of thebenzene series which contain a SO2NH2 group, especially thediazo-compounds of the following ortho-hydroxy-amines:

2,784,178 Patented Mar. 5, 1957.

ice

(a) 6 chloro 2 amino-1-hydroxybenzene-4-sulfonic acid amide,6-nitro-2-amino-1-hydroxybenzene-4-sulfonic acid amide,4-chloro-2-amino-l-hydroxybenzene-S- or -6- sulfonic acid amide,4-nitro-2-amino-l-hydroxybenzene-S- or -6-sulfonic acid amide,4-methyl-2-amino-l-hydroxybenzene-S- or -6-sulfonic acid amide,4-methoxy-2-arninol-hydroxybenzene-S- or -6-sulfonic acid amide,andGSPE", cially (b) Z-amino-l-hydroxybenzenelor -5-sulfonic acid amide.

The two latter components are to be coupled exclusively with3-aryl-5-pyrazolones, which contain an aromatically bound nitro, alkoxyor alkyl group or a halogen atom.

For couplingwith these diazo compounds containing a '-SO2NH2 group thereare used on the one hand, 3-aryl- 5-pyrazolones which contain anaromatically bound substituent not imparting solubility in water, forexample, 3-(3'- or 4'-methyl-phenyl)-5-pyrazolone,3-(4-tertiarybutylphenyl)-5-pyrazolone,-3- (2-,3'- or 4-chl0r0phenyl)-5-pyrazolone, 3-(4-fluorophenyl)-5-pyrazolone, 3-(4'- trifluoromethylphenyl) 5 pyrazolone, 3 (4'-ethoxyphenyl)-S-pyrazolone,3-(2':5-dichlorophenyl)-5-pyrazulone, 1(2'-methyl-5'-chlorophenyl)-3-phenyl-5-pyrazolone, 1-(2-, 3- or4'-chlorophenyl)-3-phenyl-5-pyrazolone,1-(3'-nitrophenyl)-3-phenyl-5-pyrazolone, l-phenyl-3-(3'-chlorophenyl)-5-pyrazolone, 1-(3-ethoxyphenyl)- B-methyl 5pyrazolone or 1-(4'-chlorophenyl)-3-(2'- chlorophenyl)-5-pyrazolone.

On the other hand, there may also be used as coupling compononets3-phenyl-5-pyrazolone and 1:3-diphenyl- 5-pyrazolone. However, these twocoupling components are to be coupled only with the diazo-componentsmentioned under (a), especially with diazotized 4-chloro-2-amino-l-hydroxybenzene-S- or -6-sulfonic acid amide.

The coupling of the ortho-hydroxy-diazo-compounds with the pyrazolonescan be carried out by the usual methods, for example, in a weakly acidto alkaline medium. 7

After the coupling reaction, the dyestuffs, for the purpose ofmetallization, can easily be separated from the coupling mixture byfiltration, if desired after the addi-' tion of sodium chloride, becausethey are only sparingly soluble in water. They are advantageously usedfor metallization in the form of filter cakes without intermediatedrying. In some cases, however it is possible to carry out themetallization directly in the coupling mixture, that is to say, withoutany intermediate separation.

.The monoazo-dyestutfs serving asstarting materials in the presentprocess, and obtainable as described above, are new and in general theydissolve so well in water in the form of their alkali compounds thatthey can be used for dyeing from baths which need no addition of acid,for example, by the single bath chroming process. I

The treatment with the agent yielding cobalt or chromium in the presentprocess is carried out under conditions such that a metalliferous azodyestuff is obtained which contains less than one atom of cobalt orchromium in complex union per molecule of monoazo-dyestufis.Accordingly, the metallization is advantageously carried out with suchagents yielding cobalt or chromium and by such methods as are known tolead to complex metal compounds of the foregoing constitution. Forexample it is generally recommended to use less than one, but at least/2, atomic proportion of cobalt or chromium per molecular proportion ofdyestufi and/ or to carry out the metallization in a weakly acid toalkaline medium. Consequently, those agents yielding cobalt or chromiumare specially suitable for the present process which are stable Y 3 inalkaline media, for example, complex cobalt or chromium compounds ofaliphatic hydroxy-carboxylic acids or dicarboxylic acids oradvantageously complex chromium compounds of aromaticortho-hydroxy-carboxylic acids, which contain the chromium bound incomplex union. As examples of aliphatic hydroxy-carboxylic acids ordicarboxylic acids there may be mentioned, inter alia, oxalic acid,lactic acid, glycollic acid, citric acid and especially tartaric acid,and among the aromatic orthohydroxy-c'arboxylic acids, there may bementioned, for example, those of the benzene series, such as 4-, 5- or6- methyl-l-hydroxybenzene-z-carboxylic acid and above alll-hydroxybenzehe-Z-carboxylic acid itself. As agents yielding cobaltthere are especially suitable, however, simple compounds of divalentcobalt such as cobalt sulfate or cobalt acetate, and if desired freshlyprecipitated cobalt hydroxide.

The conversion of the dyestutfs into thecomplex cobalt and chromiumcompounds is advantageously carriedout at a raised temperature, underatmospheric or superatmospheri'c pressure, for example, at the boilingtemperature of the reaction mixture, if desired in the presenceofsuitable additions, for example, in the presence of salts of organicacids, bases, organic solvents or other agents assisting the formationof complexes. 7

In one form of the process of the invention there is used as startingmaterial a mixture of two different metallizable monoazo-dyestutfs bothof which correspond to the above Formula '1 or one of which correspondsto that formula and the other is anortho:ortho'-dihydroxymonoa'zo-dyestufi 'free from sulfonicacid andcarboxylic acid groups. a

The ortho:ortho'-dihydroxy-monoazo-dyestufis, which come intoconsideration for carrying out the form'of the process described in thepreceding paragraph, can be obtained by coupling an ortho-hydroxy-diazocompound of the benzene series which is free from sulfonic acid andcarboxylic acid groups with'an azo component capable of coupling in aposition vicinal to a hydroxyl group, and which is free from 'sulfonicacid and carboxylic acid groups. As examples ofortho-hydroxy-diazo-compounds of the benzene series there may bementioned those obtainable from the following amines:

4- or 5 -nitro- 2-amino-l-hydroxybenzene, 4- or S-chloro-Z-aminod-hydroxybenzene, 6-acetylamino-4-nitro 2 amino-1-hydroxybenzene,4-acetylamino 6-nitro-2-aminoelhydroxybenzene,Z-amino-1-hydroxybenzene-4 methylsulfone, Z-amino-1-hydroxybenzene-4- or-5-sulfo'nic acid-N- methyl-, -N-ethyl-, -N-fi-hydroxyethyloraphenyl-amide and the other ortho-hydroxy-amines mentioned above. As azocomponents there come into consideration anaphthols such, for example,-as 5-chlorol--hydroxynaphthalene, 5z8-dichloro-l-hydroxynaphthalena andabove all p-naphthols such, for example, as Q-hydroxynaphthalene,6-bl'Ol'IlO-Z-hYdIOXf/l'lfifihthfllfillfi, 6- or 7-methony-Z-hydroxynaphthalene, 1-acetyl-, l-butyrylorl-benzoylamino-7-hydroxynaphthalene, and also l-carbomethoxyorl-carbethoxyamino-7-hydroxynaphthalene and pyrazolones such as3-methyl-5apyrazolone, hphenyl-3-methyl S-pyrazolone or1-phenyl-3-methyl-5pyrazolone-3-sulfonic acid-amide.

In this form of the process the treatment'with 'anagent yielding metalis, of course, also carried out under-conditions such that metalliferousazo-dyestuffs are obtaine'd which contain less than one atom of metal incomplex union per molecule of monoazo-dyestuff.

The products of the process of this invention'are new. They'are cobaltor chromium compounds which contain two monoazo-dyestufis, in a complex,in which the ratio of the number of cobaltor chromium atoms bound incomplex union to the number ofmonoazo-dyestuif molecules bound incomplex union to the'cobalt or chromium is smaller'than 1:1,andadvantageously about 2, and in which the two'monoazo-dyestuffs areorthozorthddihydroxy-monoazo-dyestuffs free from sulfonic acid andcarboxylic acid groups, and one of which dyestuffs, or advantageouslyboth dyestuffs, correspond to the above general Formula 1.

The new cobaltiferous and chromiferous dyestuffs are soluble in waterand also in weakly acid aqueous media, and are indeed more soluble thanthe parent metal-free dyestuffs used for making them. They are suitablefor dyeing or printing a very wide variety of materials, above all fordyeing animal materials such as silk, leather and especially wool, butalso for dyeing or printing synthetic fibers of superpolyamides orsuperpolyurethanes or poly.- acrylonitrile. In contradistinction to thechromium compounds of dyestuffs containing sulfonic acid groups, whichare advantageously usedifor dyeing from strong acid, for example,sulfuric acid, baths, the new metal compounds of monoazo-dyestutfs freefrom sulfonic acid groups are especially suitable for dyeing from weaklyalkaline, neutral to weakly acid, advantageouslyacetic acid, baths.There may, of course, be added to the dyebath the assistants customaryin the dyeing industry such as sodium sulfate, sodium pyrophosphate,ethylene oxide condensation products and the like. The dyeings soproduced are distinguished by their level character, very good'fastmessto light and very good properties of wet fastness such as a very goodfastness to washing and fulling. The dyeings are also very fast todecatizing and carbonizing.

The following examples illustrate the invention, the parts andpercentages being by weight unless otherwise stated and the relationshipof parts by weight to parts by volume being the same-as that of thekilogram to the liter:

Example 1 18.8 parts of Z-amino-l-phenol-4-sulfonic acid amide aresuspended in 50 parts of water, 14 parts of hydrochloric acid of 30percent strength are added, and diazotization is carried out at 0-5 C.with an aqueous solution of 6.9 parts of sodium nitrite. Thediazo-suspension is neutralized with sodium carbonate and added toa's'olution, cooled to 5 C., of 30 parts of l-(2- methyl-5'-chlorophenyl)-3-pheny1-5-pyrazolone in 125 parts of water, parts byvolume of a 2 N-solution of sodium hydroxide and .50 parts by volume ofa 2 N-solution of sodium carbonate. When the coupling is finished thedyestufi is filtered oifand washed with dilute sodium chloride solution.

The filter cakeis suspended in 1500 parts of water, then mixed with 125parts of a solution of sodium chromosalicylate having a chromium contentof 2.6 percent, and

. the mixture is'boiled for about '6 hours under reflux.

Thedyestuif is isolated bysalting out, and filtration, and isthendriedinvacuo. It is a .brown orange powder which dissolves-inihot:waterwith an orange coloration and-inconcentrated sulfuric .acid with ayellow coloration. The dyestuti dyeswool from weakly alkaline, neutralor acetic acid bathsred-orange tints which are very fastito light.

By dissolving the metal-free dyestufi obtainedias 'described above in'1000 parts of water and 26 parts of a sodium hydroxide-solution of 30percent strength, then adding 300 parts of a cobalt sulfate solutionhaving :a cobalt content of Y1 percent, and heating theirnixturefor ashort timeat about C., the cobalt compound of the dyestufi is obtained.When dry it is a yellow-brown powder which dyes wool from neutral orweakly acetic acid baths brownish orange-yellow tints which are veryfast to light. i

Similar dyestuffs are obtainedby treating the monoazodyestuffsobtainable from the diazoand coupling components mentioned in columns IandiII of the following table in the mannerdescribed above with an agentyielding the metal given-in column Ill, and thetints of .the dyeingsobtained with these dyestufison wool are. given in c lumn IV:

I II III IV 9 NH, Q "or m. HaNOgS 10 NH, Cr yellowish red.

HINOIS 3 11 Na, 7 c: red- HgNOgS li-"O 12 OgN NH: 110-!) 1% Qtyellowishred.

OQNH] ll l3 NH| HO-C Cr red.

\ 00 brown yellow.

Example 2 4.63 partsof the sodium salt of the dyestufl from diazotizedZ-arnino-l-hydroxybenzene 4 sulfonic acid methylamide andZ-hydroxynaphthalene;and5.02. parts of the sodium salt of the dyestufffrom diazotized 5-nitro-2- amino-l-hydroxybenzene and1-(3'-sulfonamidophenyl)- 3-phenyl-5-pyrazolone, are stirred in 200parts of water and, after the addition of 2.66 parts of a sodiumhydroxide solution of percent strength and 24 parts of a solution ofsodium chromosalicylate having-a chromium content of 2.6 percent, thewhole is heated for 3 hours under reflux. At the end of this period thechroming is complete. The dyestufi is precipitated *byneutralizationwith acetic acid, filtered off and dried. it is a black water-solublepowder which dyes wool from neutral or acetic acid baths fast greyishviolet tints.

Example 3 100 parts of well wetted wool are entered at 50 C. into adyebath which contains in 4000 parts of water 1 part of the chromiferousdyestuif obtained as described in the first and second paragraphs ofExample 1. 2 parts of acetic acid of 40 percent strength are added, thebath is carried onat the boil for /3 .hour. Finally; the wool is rinsedwith cold water and dried. There is obtained a full red-orange dyeing ofvery good fastness to washing and light.

The same result is obtainedhwhen no acetic acid is added: to thedyebath.

-entered atlO-SO C. into a dyebathwhich contains in 4000 parts of water1 part of the chromiferous'dyestufi obtained as described in the firstand second paragraphs of Example 1. 3 parts of acetic acid of 40 percentstrength are added, and the dyebathtis raised to the boil in the courseof /2 hour and dyeing is carriedon at the boil for 3/1 hour. Finally thegoods are rinsed, with cold water and dried. There is obtained a fullorange-red dyeing of very good fastness to light and Washing.

What is claimed is:

1. A member of the group consisting of an orthozor- 9 tho'- dihydroxymonoazo dyestuff which contains an aromatically bound SO2NH2- group, isfree from sulfonic acid and carboxylic acid groups and corresponds tothe formula in which R1 represents a benzene radical bound to theazo-linkage in ortho-position relatively to the hydroxyl group, R2represents a member of the group consisting of a hydrogen atom, a loweralkyl and a benzene radical, R3 represents a benzene radical, atleastone of the benzene radicals in the molecule containing a substituentselected from the group consisting of methyl, nitro, meth-'- oxy andchlorine, and a complex metal compound thereof which containssubstantially two dyestutf molecules bound in complex union with oneatom of a metal selected from the group consisting of chromium andcobalt.

2. A complex chromium compound containing one atom of chromium bound incomplex union with substantially two monoazo dyestuflf molecules freefrom sulfonic acid and carboxylic acid groups corresponding to theformula wherein R1, R2 and R3 each represent a benzene radical, at leastone of which contains a member of the group consisting of a methylgroup, a nitro group, a methoxy group and a chlorine atom and R1 isbound to the azo linkage in ortho position relatively to the hydroxygroup.

3. A complex cobalt compound containing one atom of cobalt bound incomplex union with substantially two monoazo dyestuff molecules freefrom sulfonic acid and carboxylic acid groups corresponding to theformula wherein R1 represents a benzene radical bound to me azo linkagein ortho position relatively to the hydroxy group and R2 represents achlorobenzene radical.

5. A complex cobalt compound containing one atom of cobalt bound incomplex union with substantially two monoazo, dyestuff molecules freTfr'orii snub-stared and carboxylic acid groups corresponding toth eform'ula wherein R1 represents a benzene radical bound to the azolinkage. in orthaposition relatively to the hydroxy group and Rz'represents a chlorobenzene radical.

6. A complex chromium compound containing one atom of chromium bound incomplex union with substantially two monoazo dyestutf molecules freefrom sulfonic acid and carboxylic acid groups corresponding to theformula H O OH =N-Ra ihN-=N- O SIOINHB O=N wherein R1 represents anitrobenzene radical boundto the azo linkage in ortho positionrelatively to the hydroxy group and R2 represents a benzene radical.

7. The complex chromium compound which contains .one atom of chromiumbound in complex union with substantially two molecules of the monoazodyestufi ot". the formula no on OINOI 8. The complex chromium compoundwhich contains one atom of chromium bound in complex union withsubstantially two molecules of the monoazo dyestufi of the formula HO OH(1} N=NO I C=N S OzN Hg 9. The complex chromium compound which containsone atom of chromium bound in complex union with substantiallytwomolecules of the monoazo dyestuff ofi the formula M0 OIN N==N O: I C:OINHg O h 2,7841% o 11 12 49.3151: complex vcobalt compound containingone atom of cobalt in complex union with-substantially' two at0m.;.pf ph1t jinmmplex union i h iaflymg moleoul-es-ofthemonoazo dyestufi of theformula molecules of the monoazonyestufi of the formula no 6* OH S N- If I N=N-0 I A c=N n v l OINHI .11. The complex cobalt compoundcontaining one References Cited in the file of this patent UNITED STATESPATENTS 1,623,005 Gubler et a1. Mar. 29, 1927 2,040,368 Fischer May 12,1936 2,570,052 Felix et a1. Oct. 2, 195 1 7

1. A MEMBER OF THE GROUP CONSISTING OF AN ORTHO:ORTHO''-DIHYDROXYMONOAZO DYESTUFF WHICH CONTAINS AN AROMATICALLY BOND -SO2NH2- GROUP, ISFREE FROM SULFONIC ACID AND CARBOXYLIC ACID GROUP AND CORRESPONDS TO THEFORMULA